2. INTRODUCTION
The atmosphere of the Earth is a layer of gases
surrounding the planet Earth.
The atmosphere protects life on Earth.
It becomes thinner and thinner with increasing
altitude, with no definite boundary between the
atmosphere and outer space
3. COMPOSITION OF THE
ATMOSPHERE
The atmosphere is composed of a mixture of gases, solids
and liquids.
Solids? Particles of dust and dirt that float around in the
air. Most of these particles are invisible to the human eye.
4. ATMOSPHERIC GASES
(Mixture of gases, solids and liquids)
Nitrogen - 78%
Oxygen - 21%
Water Vapor - 0 to 4 %
- Used for clouds and precipitation
Carbon dioxide – 0,37%
- Keeps the Earth warm and is used by plants to make food
Argon – 0, 93%
Traces of neon, helium, methane, krypton, xenon, hydrogen
and ozone
8. 1. TROPOSPHERE
The troposphere is the layer directly
above the earth’s surface.
It extends up from surface for 12 km. the
upper boundary of the layer is the
tropopause.
It is warmed by the earth’s long-wave
radiation, and processes like conduction
and convection.
The temperature decreases with
increasing altitude at average rate of
6,4°c/1000 m. this is called the
environmental/normal lapse rate.
All weather processes take place in this
layer.
Air pressure falls with height.
9. 2. STRATOSPHERE
The stratosphere layer extends in
altitude from 12-50 km. the upper
boundary of the layer is the stratopause.
The ozone layer is situated between 15-
35 km above the ground and is called the
ozonosphere. ozone absorbs incoming
ultraviolet radiation, which may be
harmful to humans, other animals and
plants.
The stratosphere is characterised by an
increase in temperature caused by a
concentration of ozone.
Stratosphere is the layer of the
atmosphere where planes usually fly.
Most of the jet aircraft fly in the lower
layer of the stratosphere, to avoid any
turbulence.
It acts as protective layer against
incoming meteorites.
10. WHAT IS OZONE?
Ozone is a gaseous layer in the
stratosphere that protects the
earth from harmful ultraviolet
(UV) radiation.
It is a molecule made up of three
oxygen atoms, often referenced as
O3.
11. 3. MESOSPHERE
The mesosphere layer extends
from 50-80 km.
It receives meteoric dust, which
forms nuclei.
Noctilucent clouds form from
ice crystals.
Temperature falls rapidly, with
lowest temperatures of -90°c.
ice crystals form around nuclei.
It is the coldest layer
Strongest winds are recorded
Meteors burn up due to friction
12. 4. THERMOSPHERE
The thermosphere is the uppermost
layer of the atmosphere, from 80-480
km. uppermost boundary is the
thermopause.
There is a rapid increase in temperature
with increase in height, to 1500°c.
Solar radiation is absorbed by atomic
oxygen.
13. 5. EXOSPHERE
The exosphere is the
outermost layer of the
atmosphere.
The temperature in the
exosphere goes up with
altitude.
Satellites orbit earth in the
exosphere.
14.
15. References
Bloch, T. (2017). Layers-of-Atmosphere. Available from Slideshare at
https://www.slideshare.net/ToddBloch/layersofatmosphere (Accessed 20 August 2022).
Heath, S. (2018). Layers of Earth’s atmosphere. Available from Slideshare at
https://www.slideshare.net/stevenheath148/layers-of-the-earths-atmosphere-97374909 (Accessed 20 August
2022).
Horton, S. (2015). Atmosphere. Available from Slideshare at https://www.slideshare.net/snshnecu/atmosphere-
43466985 (Accessed 20 August 2022).
Mas, P.B. (2013). Earth’s Atmosphere. Available from Slideshare at
https://www.slideshare.net/psychopamtic/earths-atmosphere-27966245 (Accessed 20 August 2022).
Roberts, C. (2008). Layers of the Atmosphere. Available from Slideshare at
https://www.slideshare.net/robertsc/layers-of-the-atmosphere-presentation?qid=c175d0ee-6d6a-408e-ba8d-
362500d52bf3&v=&b=&from_search=1 (Accessed 20 August 2022).
Volante, P.D. (2012). The layers of the Atmosphere. Available from Slideshare at
https://www.slideshare.net/patriciadanisevolante/the-layers-of-the-atmosphere-15014826 (Accessed 20 August
2022).